In his “Four Freedoms” speech to Congress, President Franklin D. Roosevelt attacked the idea that we could remain neutral in World War II. At that point in US history, many Americans were in favor of neutrality. The Neutrality Acts that had been passed in the 1930s banned most kinds of commerce between the US and countries that were at war because they did not want the US to be dragged in to another war that was not really (in their minds) essential to the United States’ national interest.
In this speech, FDR argues that there is no point in trying to remain neutral. He says that remaining neutral will not help keep us safe. He says that the dictators of the world will not wait for the US to make a move or to declare war. Instead, they will feel free to attack the US even if the US is actually neutral. He also says that, if we do not fight, we will end up in a world that is very hostile to us and dangerous for us. He says that if we do not fight, the aggressors will control the resources of all parts of the world and will then be strong enough to destroy us. He says that, if the United Kingdom is defeated, there will be nothing to prevent other countries from coming over to the Western Hemisphere and setting up bases from which they could invade the US.
In these ways, FDR argued against isolationism and for internationalism. He says that neutrality will not keep us safe and that we must, therefore, be willing to go to war.